Obesity and its associated co-morbidities are major health problems in our society, contributing to diabetes mellitus, cardiovascular disease and stroke, hypertension, and non-alcoholic fatty liver disease. The objective of this postdoctoral training program is to provide a productive learning experience in biomedical research related to obesity. This application describes a comprehensive training program that takes advantage of a cadre of distinguished faculty mentors, a strong research environment endowed with technology core facilities, an extensive array of genetically defined mouse models and established human clinical populations, and a curriculum that allows educational opportunities to augment scientific knowledge, career development, and training in the responsible conduct of research. This program is unique in that a trainee will receive mentoring from two faculty members, each of a distinct scientific team , to promote the development and execution of an interdisciplinary research project to examine the behavioral, metabolic, and molecular events that cause obesity and the metabolic syndrome. This team-approach is supported by the collaborative environment of our 26 faculty members, drawn from 14 different Departments and Centers that have been organized into four teams to focus on The Central Regulation of Energy Metabolism (Team 1: Neuroanatomy, Neurobiology, Psychiatry), The Molecular Biology of Energy Metabolism (Team 2: Biochemistry, Molecular Genetics, Molecular Biology, and Physiology), In vivo Intermediary Metabolism (Team 3: Advanced Imaging, Human Nutrition, Hepatology/Gastroenterology), and Human Genetics and Energy Metabolism (Team 4: Bariatric Surgery, Clinical Epidemiology, and Genetics). Individuals accepted into this program will have a Ph.D., M.D./Ph.D., or M.D. degree and will have acquired some experience in one of many disciplines integral to this work prior to beginning their three-year fellowship. However, their training with two mentors, and work in two or more collaborative laboratory settings will allow them to become fluent in multiple, often disparate scientific languages (e.g. molecular biology, radiology, neuroanatomay,. nutrition, psychiatry, human genetics) thus permitting them to critically address unique scientific problems in an interdisciplinary manner. This program is designed, therefore, to train individuals who will become effective teachers and investigators capable of cutting-edge research in obesity.